Abstract
The structure and molecular conformation of model compound copolypeptides related to silk sericin, which were polymerized in acetonitrile or in dioxane system, were investigated by means of infrared spectroscopy, x-ray diffraction and circular dichroism. A close similarity between the model compounds and silk sericin was observed in crystal structure and in molecular conformation. Infrared spectra indicate that the as-polymerized polypeptide related to silk sericin exhibited the anti-parallel β structure. It was demonstrated that model compounds were α mixture of random coil conformation (ca. 50%) and the β structure (ca. 50%) by comparing the observed and calculated circular dichroism curves. Granule forms with a diameter of 0.3-0.5μm were observed for all the as-polymerized model compounds by the scanning electron micrograph.
